U.S. Pat. No. 5,024,139 (Knight) discloses a semi-automatic, double action only pistol with a rotating barrel that is disassembled upon the removal of the magazine and the manipulation of a lever located on the frame by turning the lever 90°. This rotation brings a notch out of the way of a barrel lug thus allowing the slide to move forward until it disengages from its guides on the frame. The pistol according to U.S. Pat. No. 4,984,504 (Beretta) also uses a lever located on the frame for disassembly.
U.S. Pat. No. 1,427,966 (Nickl) discloses a similar rotating barrel pistol that is designed with a disassembly mechanism located in the frame. One of the main differences between Nickl and Knight/Beretta is that the disassembly mechanism in Nickl is a pin that must be pushed against a spring perpendicular to the symmetry plane of the pistol in order to allow the displacement of certain parts in the slide.
The content of the three mentioned documents is hereby incorporated by reference in their entireties for all purposes, and shall therefore become an integral part of this description for all jurisdictions in which this is possible.